Simultaneous recording of electrical activity and the underlying ionic currents in NG108-15 cells cultured on gold substrate

Abstract

This paper shows the simultaneous recording of electrical activity and the underlying ionic currents by using a gold substrate to culture NG108-15 cells. Cells grown on two different substrates (plastic Petri dishes and gold substrates) were characterized quantitatively through scanning electron microscopy (SEM) as well as qualitatively by optical and atomic force microscopy (AFM). No significant differences were observed between the surface area of cells cultured on gold substrates and Petri dishes, as indicated by measurements performed on SEM images. We also evaluated the electrophysiological compatibility of the cells through standard patch-clamp experiments by analyzing features such as the resting potential, membrane resistance, ionic currents, etc. Cells grown on both substrates showed no significant differences in their dependency on voltage, as well as in the magnitude of the Na+ and K+ current density; however, cells cultured on the gold substrate showed a lower membrane capacitance when compared to those grown on Petri dishes. By using two separate patch-clamp amplifiers, we were able to record the membrane current with the conventional patch-clamp technique and through the gold substrate simultaneously. Furthermore, the proposed technique allowed us to obtain simultaneous recordings of the electrical activity (such as action potentials firing) and the underlying membrane ionic currents. The excellent conductivity of gold makes it possible to overcome important difficulties found in conventional electrophysiological experiments such as those presented by the resistance of the electrolytic bath solution. We conclude that the technique here presented constitutes a solution to the problem of the simultaneous recording of electrical activity and the underlying ionic currents, which for decades, had been solved only partially.

Electro‐Stimulation, a Promising Therapeutic Treatment Modality for Tissue Repair: Emerging Roles of Sulfated Glycosaminoglycans as Electro‐Regulatory Mediators of Intrinsic Repair Processes

“…[ 73 ] Thus, intracellular ion‐currents and membrane potentials can be measured in NG108‐15 cells cultured on gold surfaces. [ 74 ] Atomic force microscopy and SEM are also useful for the characterization of these cultured neurons [ 75 ] and facilitates the determination of specific roles for regulatory ion channels, [ 76 ] regulated by G‐coupled receptors [ 77 ] and sensory filopodia. [ 78 ] The GAG chains of KSPGs and associated counter‐ions (Ca2+) serve as intracellular ion‐reservoirs or ion‐traps and promote these electro‐physiological processes.…”

Functional Consequences of Keratan Sulfate Sulfation in Electrosensory Tissues and in Neuronal Regulation

“…[96,97] Endogenous currents have been detected in many developing nervous systems. [98][99][100] Direct current (DC) electric fields applied to culture vessels can stimulate and guide axonal regrowth. [97] Stem cell and stem cell-derived neural cells are guided by DC electric fields raising the possibility that this approach could also be useful therapeutically in neural repair.…”

“…[267][268][269] Culture of NG108-15 cells on gold surfaces has improved the analysis of intracellular ioncurrents and membrane potentials in cultured neurons. [98] AFM and SEM has also been applied to the characterization of these cells [270][271][272] and to determine the roles of regulatory ion channels, [273,274] and how these are modulated by G-coupled receptors [275] and the sensory input of fillopodia in neuronal cultures. [276] The GAG chains of KSPGs and their associated [248] Copyright 2014, The Authors, published by Elsevier B.V.…”

“…Directional axonal growth and neural cell migration are crucial in the regeneration of the CNS and guided by a large number of accessory KS interactive proteins . Endogenous currents have been detected in many developing nervous systems . Direct current (DC) electric fields applied to culture vessels can stimulate and guide axonal regrowth .…”

“…The culture of neurons on peptide coated gold surfaces and multielectrode microarrays has facilitated the measurement of generated membrane action potentials and whole‐cell ion currents . Culture of NG108‐15 cells on gold surfaces has improved the analysis of intracellular ion‐currents and membrane potentials in cultured neurons . AFM and SEM has also been applied to the characterization of these cells and to determine the roles of regulatory ion channels, and how these are modulated by G‐coupled receptors and the sensory input of fillopodia in neuronal cultures .…”